Electrical discharge device and base



- Oct. 19, 1948- 1. ZAMBAKIAN ET AL I ELECTHICAL: DISCHARG DEVICE AND BASE Fild Aug. 20, 1946 Patented Oct. 19, 1948 UNITED S'TATES PATENT OFFICE ELECTRICAL DISCHARGE DVICE AND BASE Irving Zambakian, Bloomfield, and Ward W.

Watrous, Jr., Chatham, N. J., assignors to Westinghouse Electric Corporation, East Pittshurgh, Pa., a corporation of Pennsylvania Application August 20, 1946, Serial No. 691,836

(Cl. al- 275) 18 Claims. 1

This invention relates to electrical discharge devices and more particularly topa novel form of lbase therefor.

The principal object of our invention is to provide a base construction which is adapted to be connected to an associated envelope in a secure manner, while at the same time providing means to avoid undue heating of said envelope during operation.

Another object of our invention, generally considered, is to provide an improved form of base which is interchangeable with other forms commonly used, but which may include an upper 'skirt or hollow cylindrical portion to receive the lower portion of the envelope of said device, said 'skirt carrying internal ribs adapted to form air carrying ducts along 'said envelope, and said base having one or more apertures admitting cooling air to said ducts.

A further object of our invention is to provide a .base for an electrical device comprising a normally lower hollow cylindrical portion with a plurality of electrical contacts projecting from a bottom closure thereof, an upper hollow cylindrical portion of larger diameter to receive the lower portion of the envelope of said devi-ce and iconnected to said lower cylindrical portion by la wet)l outstanding peripherally from the latter, said lower cylindrcal portion carrying internal ribs some of which may form air-carrying ducts along said envelope, said 'bottom closure having an aperture through which air for -cooling may flow to said ducts, said upper hollow cylindrical portion also oarrying ri'bs forming air ducts along said envelope, and said connecting 'web being apertured to allow air to flow to said ducts.

A still further object of our invention is to provide a base for an electrical device comprising a hollow cylindri-cal cement-carrying portion with a plurality of electrical contact elements projecting from a bottom closure thereof, said cylindrical portion carrying internal ri'bs so that some of them -may form air-carrying ducts along the envelope of said device when in place, while the others carry basing cement, said bottom closure having an aperture through which air for cooling may flow to said ducts.

Other objects and advantages of the invention will become apparent as the description proceeds.

Referring to the scale drawings: w y

Fig. 1 is a fragmentary elevational view of a thyratron embodying our invention. i

Fig. 2 is a bottom plan View of the device illustrated in Fig. 1.`

Fig. 3 is a fragmentary axial sectional view of the device, on .the line III-III of Fig. 6, in the direction of the arrows.

Fig. 4 is a -fragmentary axial sectional view of the device on the line IV-IV of Eig. 6, in the direction of the arrows.

Fig. 5 isya fragmentary axial sectional View of the device onthe line V-V of Fig. 6, in the direction of the arrows.

Fig. 6 is a plan of the base illustrated in Fligs. 3, and 5.

' Fig. 7 is an axi-al sectional view, on the line VII-VII of Fig. 6, in the direction of the arrows.

Fig. 8 is a perspective view of another base embody'ing our invention.

Pig. 9 is a plan of the base of Fig. 8, slightly modified in that eight internal ribs -are shown instead of six. i

In electrical devices, such as mercury vapor thyratron's and rectifiers, the temperature of the condensed mercury vapor is of prime importance. In' general, it is desired to keep such temperature low, without using additional equipment for cooling or inoreasing the length of the envelope. Also it is frequently necessary to have additional connections on a standardized mercury-vapor tube base, without requiring a new socket or changing existing sockets. Such may be accomplished lby adding a shirt or h-ollow, cylindr'cal projection on the top of the base, and bringing out a new connection or connections on the side of this skirt, as described and claimed in the Watrous application, Serial No. 532,730, filed April 26, 1944, now Patent No. 2,4%,462 dated July 20, 1948 and 7 owned -by the assignee of the present application.

The presence 'of such a skirt, however, reduces bulb cooling and herice raises the temperature of the condensed mercury. i

In order to overcome this temperature rise, we have provided a series of ribs |on the inside of the skirt, and a series of holes around the bottom of the skirt. The bulb or envelope of 'the electrical device may then be cemented into the lower portion of the base in the usual manner, and the ribs on the skirt engage the bulb and define air ducts therealong', and/ or some of the skirt rihs may carry cement lbetween the air ducts. This combination of ribs and apertures provides for bulib cooling, and hence results in reducing the temperature of the ycondensed mercury, as the air around the tube heated -by radiation and conduction causes convection currents, drawing in cooler air from the bottom of the base toward the tube. Such cool air passesV through the holes, along thejducts over the bulb wall and out, thereby cooling it to the desired extent.

Referring now to the embodiment of our invention illustrated in Figs. 1 to '7, inclusive, there is shown a thyratron 11 comprising a glass or vitreous envelope 12, which is evacuated and provided with a small quantity of ionizable filling material, such as the vapor of mercury or other suitable material, and/or inert gas. The envelope is provided with a rentrant glass stem 13, through the press 14 of which extend lead wires making connection With exterior contact elements or terminal prongs 15 on the bottom of the attached base 16 to connect some of the enclosed elements with leads to associated apparatus (not shown). The opposite end of the envelope may be constricted, capped, and have a terminal member which makes connection with the anode of the device, (not shown) as in the Watrous application, previously referred to.

Opposed to the anode, and suitably supported by lead-in wires 1'1 and 18, is a cathode generally designated 19, which maybe of any suitable construction, for example, such as described in detail and claimed in the Watrous application, Serial No. 525,659, filed March 9, 1944, now Patent No. 2,424293, datedJuly 22, 19.47, and owned by the assignee of the present application. A suitable heater, (not shown) may also be provided for the cathode, if a filamentary or selfheating cathode is not used, leads from the cathode and opposite ends of the heater therefor connecting respectively with the two prongs 15 disposed rearwardly, as illustrated in Fig. 1.A

Between the cathode 19 and the anode, (not shown) is a control grid generally designated 21, which is desirably of the form described and claimed in Patent No. 2,381,632, dated August 7, 1945, that is, it has a single circular opening for the passage of electrons, said opening being desirably coaxial with the cathode and the anode. Instead of making a connection with the grid 2| through the side of the envelope 12, in accordance with the Livingston Patent No. 2,044,618 for example, we, in the present instance, carry the lead 22 therefrom to one of the contact prongs 15, in this instance preferably the right-hand front prong, as viewed in Fig. 1.

The discharge between the cathode and anode is desirably confined by shield-grid devices, including a hollow cylindrical section 23 around the cathode and extending along to about the center portion of the grid 21, and an upper hollow cylindrical section, (not shown) each section desirably having an annular transverse bale, and being otherwise constructed in accordance with said Watrous patent, previously referred to.

The shield-grid sections are desirably carried by supporting wires 24, in turn carried by a collar 25 applied to a stem 13 and clamped securely thereto. These wires project upwardly on the outside of said shield grid sections in contact with the outer surfaces, being welded or other-- wise secured thereto. The upper ends of the wires may be used to brace the assembly in a manner described and claimed in the Watrous Patent No. 2353375, dated July 18, 1944. A suitable connection for the screen-grid sectionsis made between one of the support wires 24 and the remaining one of the prongs 15.

The base 16 of the device illustrated, isdesirably formed from suitable insulating material such as uBakelita some other plastic, glass, or metal with insulating inserts. The lower section 26 is hollow and generally cylindrical, with la customary locking pin 50 on its side. Its lower end is closed by a wall 21, which is therefore generally circular, and in which the upper portions of the prongs 15 are fastened, in a conventional or suitable manner. The diameter and height of the section 26, as well as the size of the prongs 15, may be conventional, so as to interchange with other electrical devices.

The upper portion 28 is generally hollow-cylindrical, with its inner surface, however, desirably frustoconical or flaring upward slightly so as to nestingly receive the lower portion of the envelope 12. The lower part of said hollow cylindrical portion 28, is connected with the upper edge of the lower section 26 by an annular web '29, which may also be considered as an inwardly extending fiange on said upper cylindrical portion 28. Of course, the diameter of the portion "23 is determined by the size of the envelope,

the lower portion of which it receives.

In order to provide for the desired cooling of any condensed mercury or other Vapor in the lower ,portion of the envelope 12, the following described improvements, or some of them,fmay be employed. The inner surface of the lower cylindrical portion 26 is desirably corrugated, serrated, or formed with inwardly projecting ribs 31, which engage the restricted extreme lower portion of the envelope 12, and hold basing cement 32 between some or all of them, for looking thebulb 01' envelope 12 in place. If such cement is disposed between only some of said ribs 3 I the remaining spaces between the ribs define air ducts 33 along the envelope 12 when in place, 4as viewed in Fig. 3.

l'n order to admit air to said ducts, thebottom closure portion 21 of the base 16 is desirably provided with an aperture 3,4, which in thepresent instance is formed as a partially curved slot between one of the contact elements -15 and the remaining contact elements, thereby performing the double function of admitting Cooling air and increasing the length of the leakage path and corresponding resistance between said element 15 and the remaining ones. The air currents caused by convection during the use of the device are indicated by the arrow 35 in Fig. 7 and the arrows 36 and 3'1 in Fig. 3, and 38 inFig. 4.

In order to allow for the air, representedby the arrow 38, to pass out along the envelope 12, the cylindrical portion '28 desirably carries internal ribs '39, 40, 41 and 42 which may have cylindrical or alternately parallel, except for nominal draft, rather than frustc-conical or fiaring inner surfaces, and engage the adjacent surface of the envelope 12 to define air ducts 43 therealong. In order to admit additional air for cooling along the bulb surface enclosed bythe upper portion 28 of the base, or in'case the ducts 33 are also closed by base cement 32, a series of apertures 44 are provided in the web 23 to allow suchair, indicated by the arrow 45, to pass along the bulb surface and out as, or with, the air indicated by the arrow 38.

s an alternative, the inner surface of the cylindrical portion 28 may also carry several sets of ribs 46, fourfor example, each set being desirably equally spaced between a pair of the ribs 39, 40, 41, 42, and positioned fairly close together so as to, if desired, confine basing cement 4'1 instead of, or in addition to, the basing cement 32 between the ribs 31. Such a construction, therefore, makes the base more adaptable and provides for the very secure connection of the envelope ror bulb 12 to the base'16,^while at the same'time'not interfering with the circulation of air in a manner as previously described. The lower ends of the ribs 46 are desirably extended to prevent basing cement from flowing over to the holes 44, and simultaneously provide more basing area.

If, as previously suggested, it is desired as an alternative, to have a contact cap 48 on the side of the cylindrical skirt 28, such a cap, generally formed as in the Watrous application previously referred to, may be connected to saidskirt ,by self-tapping screw 49, passing into acorresponding hole in said skirt portion. 'i Instead of making the cap 48 interlock with a portion of the skirt, as in said Watrous application, the edge thereof may merely be formed to snugly engage the cylindrical surface of said skirt, as illustrated.

In order to allow for convenient connection between a lead from the envelope lz and said cap 48, a groove is formed in the top of the lower portion 26, as illustrated in Figs. 6 and 'Land a hole 52 is formed in the skirt 28, so that such lead may be fitted in the groove 5| and passed through the hole E2 to connect with the inner surface of the cap 48, in any desired manner, as by means of spot welding as in the Watrous application referred to.

.Referring now to the embodiment of our invention illustrated in Figs. 8 and 9, there is shown a base ISP' which is unprovided with an upper extension of larger diameter like the base IB. Instead, it is shown formed as a cylindrical portion 2138L closed by a circular portion 21a carrying contact prongs If)a and formed with a central aperture 34a for the admission of cooling air.` The inner surface of the hollow cylindrical portion 26a carries ribs 45a, preferably either six as illustrated in Fig. 7, or Veight as illustrated in Fig. 8.

When assembled with the envelope |2a of an electrical device, every alternate groove defined between the ribs 45a is desirably filled by basing cement for securing the envelope thereto, the remaining grooves forming air-carrying passages 43a along the surface of said envelope |2fl, the air normally circulating by convection up through the central aperture 34a along the ducts 43a and out, as in the previous embodiment, except that the air in the present embodiment passes along only one set of ducts. i

If desired, the aperture 34a in the circular portion 2'!a of the base la may be through the center of an orienting projection, such as used on Octal bases for radio receiving tubes. The socket receiving such a base may have a corresponding aperture registering with said base aperture so as to allow air to circulate through said base and around the received portion of the envelope.

From the foregoing disclosure, it will be seen that we have provided a base for an electrical device which is formed lwith one or more sets of ribs defining ducts along whichair normally passes by convection during operation of the device for cooling the bulb to reduce the temperature of the mercury or other condensate therein,` if

used. An additional advantage is that the employment of an additional bulb-encircling portion on the base increases the strength of the connection with respect to the envelope of the device, as the basing cement is molded into angular spaces, which prevents relative movement between the base and the envelope, evenif the cement does not adhere to the material ofl the base. The serrations or projections provide additional cement-bonding surface and change the manner of stressing the material of the cement, that is, compression is substituted for shearing'whereby the connection will standgreater stress before yielding.

,l Insummary, it is pointed out that the foregoing inventioninvolves two distinctfeatures: (I) the provision forecooling the `condensed mercury, or other 'vaporizable' .'materiaL such as sodium, which may zbe-,usedrand (2) the provision for a more secure attachment of the base to the envelope. The fiutingor corrugations on the inside surface -of the base provide greater cement-engagingy area, perform theimportant function of obtaining greater torsional grip, and in addition may provide passageways for the circulation of air for .cooling purposes.

i In the embodiment of Figs.` 1 to '7, inclusive, the skirt28 is provided for three reasons-first, to support a side cap, if used; second, to provide for additional basing support; and third, for appearance.` The air passages provided between the skirt and the envelope overcome the loss of cooling area -due to the addition of the skirt. The embodiment illustrated in Figs. 1 to 7, inclusive, is a special discharge device,iwhile'the' embodiments illustrated in Figs. 8 and 9, may be of more f general application to a line' of tubes.

Although preferred embodiments of our invention have been described,lit will be understood that modifications may be made within the spirit and scope of the appended claims.

We claim:

1; A base for an electrical device comprising a hollow cylindrical cement-carrying portion with a bottom closure, and a plurality of electrical contact elements projecting therefrom, said cylindrical portion carryng internal ribs some of which form air-carrying ducts along the envelope of said electrical device when in place, said bottom closure having an aperture through which air forcooling may flowto said ribs.

i 2.`A base for an electrical device comprising a normally lower hollow cylindrical cement-carrying portion with a bottom closure, a plurality of electrical contact elements projecting therefrom, a normally upper hollow cylindrical portion of larger diameter to receive a normally lower portion of the envelope of said device, and a, web connecting said `normallyupper cylindrical portion to` said normally lower cylindrical portion and outstanding peripherally from the '1atter, said normally lower cylindrical portion carrying internal ribs some of which form air carrying ducts along the envelope of said electrical device when the latter is in place, said bottom closure portion having an aperture through which air for cooling may flow to said ribs.

3. A base for an electrical device comprising a hollow cylindrical portion, a generally circular member closing the bottom thereof, a plurality ofJ electrical contact elements projecting' from said lcircular member,` said cylindrical portion carrying a plurality of circumferentially-spaced ribs projecting inwardly, extending from said circular portion to 'the periphery of said cylindrical portion, and-defining ducts along the envelope of said electrical device, for alternately receiving `basing'cenent and cooling air, a central portion of said circular closure part being apertured for admitting air to said ducts.

4. A base for an electrical device comprising a normally lower hollow cylindrical cement-carrying portion with a bottom closure, a plurality of electrical contact elements projecting therefrom, and a normally upper hollow cylindrical portion of larger diameter to receive the normally lower portion of the envelope of said device and conansncoo nected to said lowercylindrical-portion'bya web outstanding peripherally from the latter, said upper hollow cylindrical portion carrying internal ribs adapted to engage said envelope 'and -form air carrying ducts therealong, said 'web having an aperture communicating` with the 'spaces' between said ribs for admitting airto said ducts.

5. A base for an electrical device'comprising a normally lower hollow cylindrical cement-carrying portion with a bottom closure, a plurality of electrical contact elements projecting therefrom, and a normally upper vhollow cylindrical portion of larger diameter to receive the lower portion of the envelope of said device and connected to-'said lower portion by a web outstanding peripherally from the latter, said Vnormally lower cylindrical portion carrying 'internal ribs, some of :which form air-carrying ducts along 'theenvelope of said electrical device when-ithe=latter is`in place, said bottom closure .portion :having `an vaperture through which air fcr-coolingmay'flowftousaid ducts, said upper hollow cylindrical portionl carrying internal ribs adaptedvto engage'the-envelope of said electrical device and form air-carrying ducts therealong, said web having an ,aperture communicating with the spaces-'between said 'ribs for admitting air to said ducts.

6. A basevf'or anelectrical device comprising a normally lower hollowcylindrical cement-carrying portion with a plurality of electrical contact elements projectingfroma bottom closure thereof, and a normally upper hollow cylindricallportion of larger diameter to receive the lower portion of the envelope of said device and connected to said lower cylindrical portion by a web outstanding peripherally from the latter, said upper hollow cylindrical portion carrying internal ribs some of which are adapted to engage the envelope of said electrical device and form air lcarrying ducts therealong land other of which may hold cement =for connection .with said envelope,'said webhaving an aperture communicating with the spaces between sadiribs foradmitting ai-r to said ducts.

7. A base for an electrical device comprising a normally lower hollow cylindrical cement-carrying portion with a plurality of electrical contact elementsprojecting from a'bottom closure-.thereof, and a normally upper hollow cylindrical portion of larger diameter t-ol receive'thelcwer portion of the envelope 'of said deviceV and connected to said lower portion 'by aweb outstanding peripherallyffrom the 1atter,said normally lower cylindrical portion carrying internal ribs, some of which form air-carryingducts along theenvelope of said electrical device when'the latter is inplace, said bottomV closure portion 'having an aperture through which air for cooling may fiow to said ducts, said upper hollow cylindrical portion carrying internal ribs some of vwhich 'are adapted to engage the envelope of said electrical device and form air-carrying ducts therealong and others of which may confine cement for connection with said envelope, said web having an aperture communicating with the spaces between said t ribs for admitting: air to `saidl ducts.

8. An electrical device comprising'an' evacuated envelope, enclosed ionizable materiaL'electrodes, and abase comprising a normally lower portion with a plurality of contact elements lrespectively connecting with some of said enclosed elements to connect them with 'leads to associated lapparatus, a hollow cylindricallportioncarrying internal ribs,` and basing cement'disposed between some of 'said ribs and the engaged portion of the 8 envelope, air-.carrying ducts along said envelope being provided by the spaces unoccupied by said cement, said lower portion having an aperture through which air for cooling may flow to said ducts.

9. An electrical device comprising an evacuated envelope, enclosed ionizable material, electrodes, and Ia base comprising a normally lower hollow cylindrical portion with a bottom closure, a plurality of .electrical contact elements respectively connecting with some of said enclosed elements, vto connect them with leads to associated apparatus, and vprojecting from said closure, a

` normally upper hollow cylindrical portion of larger diameter and receiving a normally lower portion of the envelope of saiddevice, and a web connecting said normally upper portion lto said lower cylindrical portion and outstanding peripherally from the latter, said vnormally lower cylindrical portioncarrying internal ribs, some of which carry cement connecting the base to said envelope, air-carrying ducts .defined lalong said envelope by some of said ribs, said bottom closure portionr having an aperture through which air for cooling fiows to said ducts.

10. An electrical device comprising an evacuated envelope, enclosed ionizable .material comprising mercury, electrodes, 'and a base on said device comprising a hollow cylindrical portion, a generally circular member closing the normal bottom thereof. a plurality of electrical contact elements pi'ojecting :from said circular member, said cylindrical portion carrying a plurality of circumferentially .spaced ribs projecting inwardly, ex-

- tending from said circular portion to the periphery of said cylindrical portion and defining ducts along said envelope, -basing cement in alternate ducts and securing said base to said envelope, the other ducts for carrying cooling air, a central i portion of said closure part being apertured for admitting such air.

11. lAn electrical device comprising an evacuated envelopefenclosed ionizable material comprising mercury, electrodes, and a base on said device comprising a normally lower hollow cylindrical portion witha bottom closure, a plurality of electrical contacts projecting therefrom and connecting respectively with some of said enclosed elements, and a normally upper'hollow cylindrical portion of larger diameter receiving the lower portion of said envelope and connected to said lower cylindrical lportion by a web outstanding peripherally from the latter, said upper hollow cylindrical portion carrying internal ribs engaging said envelope and forming air carrying ducts therealong, said web having an aperture for admitting air to said ducts.

12. An electrical device comprising an evacuated envelope, enclosed ionizable material comprising mercury, electrodes, and a base on said device comprising a normally lower portion with a plurality of contact elements respectively connecting with some of said enclosed elements and to connecimthem with leads to associated apparatus, `and a normally upper hollow cylindrical portion of larger diameter, receiving the lower portionv of said envelope, and connected to said lower portion by a web outstanding peripherally from the latter, said normally lower portion carrying internal ribs, some of which form aircarrying ducts along said envelope, cement between some of said ribs connecting said base and envelope, said lower portion having an aperture for the admission of said cooling air to said ducts, ribs on said upper hollow cylindrical portion engaging said envelope and forming air carrying ducts therealong, said web having an aperture admitting air to said ducts.

P3. An electrical device comprising an evacuated envelope, enclosed ionizable material comprising mercury, electrodes, and a base on said device comprising a normally lower hollow cylindrical portion with a hollow closure, a plurality of electrical contacts projecting therefrom and connecting respectively with some of said enclosed elements, and a normally upper hollow cylindrical portion of larger diameter receiving the lower portion of said envelope and connected to said lower cylindrical portion by a web outstanding peripherally from the later, said upper hollow cylindrical portion carrying internal ribs some of which engage said envelope and form air carrying ducts therealong and others of which confine cement which secures said envelope to the base, said web having an aperture for admittimeair to said ducts.

14. An electrical device comprising anlevacuated envelope, enclosed ionizable material comprising mercury, electrodes, and a base on said device comprising a normally lower portion with a plurality of contact elements respectively connecting with some of said enclosed elements and to connect them with leads to associated apparatus, and a normally upper hollow cylindrical portion of larger diameter, receiving the lower portion of said envelope, and connected to said lower portion by a web outstanding peripherally from the latter, said normally lower portion carrying internal ribs, some of which form alr-carrying ducts along said envelope, cement between some of said ribs connecting said base and envelope, said lower portion having an aperture for the admission of said cooling air to said ducts, ribs on said upper hollow cylindrical portion some of which engage said envelope and form air carrying ducts therealong and others of which confine cement securing said envelope to said base, said web having an aperture admitting air to said ducts.

15. A base for an electrical device comprising a hollow generally-cyllndrical cement-carrying portion closed at one end, and electrical contact means projecting from said closed end, said cylindrical portion carrying internal longitudinally-extending ribs, some of which form aircarrying ducts along said envelope when the base is in place.

16. A base for an electrical device comprising a normally-lower hollow cylindrical cementcarrying portion with a normally-bottom closure, electrical contact means projecting therefrom, a normally-upper hollow cylindrical portion of larger diameter to receive a normally-lower portion of an envelope of said device, the normallybottom edge of said normally-upper portion being connected to the normally-top edge of the normally-lower portion, said normally-lower portion being formed with internal ribs to provide air ducts along the envelope When the base is in place.

17. A base for an electrical device comprising a hollow cylindrical portion, a generally circular member closing the normally-bottom end thereof, electrical contact means projecting from said circular member, said cylindrical portion carrying a plurality of circumferentially-spaced inwardlyprojecting ribs defining ducts along the envelope of said device for alternately receiving basing cement and carrying cooling air.

18. A base for an electrical device comprising a normally-lower hollow cylindrical cementcarrying portion with a bottom closure, electrical contact means projectng therefrom, a normallyupper hollow cylindrical portion of larger diameter to receive the normally-lower portion of the envelope of said device, and Web means outstanding peripherally from -the latter and connecting it to said normally-upper portion, said upper hollow cylindrical portion being formed with internal ribs adapted to form air-carrying ducts along said envelope when the base is in place.

IRVING ZAMBAKlAN. WARD W. WATROUS, JR.

No references cited. 

